I’ve had my OPPO since 2017. Just now I discovered there’s one input which does not process the digital input to all channels but instead sends stereo direct to DAC, then off to the front channels only, so no bass management, no sub output. This is the usb B input. For awhile today I thought the OPPO was broken. It is not yet to get bass it looks like I will need to output to A/V Pre-Pro. Just thought I would share this discovery. Now I know why music from iTunes on computer seemed a little bass lite.